Via at least one deformable membrane made of fibre composite material, membrane compensating couplings allow the compensation of angle and length deviations which occur between rotating machine elements during operation, for example an output element of an engine and an input element of a driven unit, for example a transmission. Since the service life of a membrane made of fibre composite material depends greatly on the deformations occurring thereon, a misalignment of the machine elements to be coupled should as far as possible be avoided in the static installed state. Accordingly, compensating couplings comprising membranes made of fibre composite material are preferably used wherever a drive unit mounted elastically to isolate vibrations has to be connected to a fixed transmission or a subsequent drive train. The dynamic changes in the alignment angle and in the distance between the machine elements to be coupled which occur here are compensated by a curving of the membrane. In the radial direction, on the other hand, a membrane is relatively rigid. To compensate large radial displacements, at least two membranes at the greatest possible axial spacing are required.
A one-piece membrane compensating coupling made of fibre composite material is known from AT 395 900 B. This coupling comprises two pre-manufactured membranes which are permanently connected via a tube section. However, the necessary adhesive bonding of the membranes to the tube section using an additional sleeve is extremely complicated in manufacturing terms and therefore cannot take place at the installation site. Moreover, the axial length of such couplings which can be handled is often very greatly restricted due to the spatial conditions at the installation site, such as for example in the engine room of a ship. Since such couplings are usually installed after the drive unit or the transmission, in the case of larger spacings a coupling according to AT 395 900 B can no longer be brought to the installation site or can be brought there only with great difficulty or cannot be removed again without being destroyed. Furthermore, due to the fact that the fixing elements are located radially far out, relatively high inertias occur, which are usually undesirable with regard to torsion vibrations.
A further membrane compensating coupling is known from AT 403 837 B. This comprises two compensating elements, in each case comprising a deformable membrane made of fibre composite material, on the outer circumference of which a tube section is integrally formed. The two tube sections are releasably connected to one another via fixing screws. However, due to manufacturing reasons, such membrane compensating couplings can be produced only with a small axial length, since the membranes are usually produced manually. Moreover, as in the coupling according to AT 395 900 B, relatively high mass moments of inertia occur on account of the fact that the fixing elements are located radially far out.
It is also proposed in AT 403 837 B to pre-manufacture the membrane parts and tube sections as individual parts and then to connect them by means of adhesive bonding or screwing to form a construction unit. In the first-mentioned case, this again leads to a considerable manufacturing complexity, while in the last-mentioned case the mass moments of inertia increase further.
Finally, a membrane compensating coupling according to the preamble of claim 1 is known from EP 1 526 299 A1. In this case, too, use is made of two separate compensating elements made of fibre composite material. Each compensating element comprises a deformable membrane and a stiffer membrane located opposite the first. Both membranes are integrally connected to one another at their outer circumference. Moreover, a tube section is integrally formed on the stiffer membranes, which tube section forms at its free end a radially outwardly directed connecting flange. The two tube sections are releasably connected to one another at the connecting flanges by means of fixing screws. In the assembled state, this coupling is installed for example between a drive unit and a transmission. In order to permit fixing of the compensating elements to corresponding flanges of a drive unit and a unit to be driven from the side of the coupling, the respective outer membrane has fixing openings and the further membrane has through-openings located in front of these. This design permits lower mass moments of inertia; however, the axial length of the coupling and thus also the possibility of compensating large radial and angle changes is limited for manufacturing reasons. The shape of the compensating elements is furthermore very complicated to produce.